
½ cup butter, softened
1 cup packed brown sugar
1 egg
1 teaspoon vanilla extract
6 tablespoons unsweetened cocoa powder
1⅔ cups all-purpose flour
½ teaspoon baking soda
½ teaspoon salt
½ cup milk
1 cup chopped English walnuts
30 walnut halves
6 tablespoons butter, melted
½ cup unsweetened cocoa powder
2 cups confectioners' sugar
¼ cup milk
¾ teaspoon vanilla extract